Thermoplastic material, such as butyl rubber, is an excellent sealant and gasket, and is often used in such applications. However, due to the tacky nature of the material, handling, dispensing and shaping such material is very difficult. When tacky material in the form of sheets is laid upon themselves, or if in the form of a strip and wound upon a spool, the material "flows" together rendering separation and dispensing of the sheets or strips very difficult, if not impossible, and various techniques and apparatus have been employed to aid in the handling of such compositions.
A most common approach to improving the handling and separation of tacky material such as butyl has been to use a powder, such as talcum powder, to coat the surface of the material to render the same substantially non-tacky. While powdering the surface of the material does aid in the handling thereof, the shelf life of such powdered material is relatively short as the material will "bleed" through the powder, particularly at higher ambient temperatures, and it is not possible to accurately control the uniformity of powder distribution. Additionally, material treated with powder is troublesome to handle and creates unpleasant working conditions.
It has been proposed to improve the handling characteristics of tacky material in tape form by coating the tape with protective covering, such as shown in U.S. Pat. Nos. 2,105,881 and 2,940,884. Also, in U.S. Pat. No. 2,541,498 it has been proposed to utilize polyethylene film with tacky material to maintain the separation of sheets of tacky material, and this patent recognizes that the film may be compatible with the material for blending therewith.